Structural alloy steel 38HA, 37Cr4, 1.7034 for medium-duty parts used in the construction of vehicles, engines and machines according to PN-72 / H-84030.
| Standards | Steel Grades | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chemical Composition % | |||||||||||||
| C: | Mn: | Si: | P: | S: | Cr: | Mo: | Ni: | V: | Ti: | Cu: | N: | W: | |
| PN | 38HA | ||||||||||||
| 0.35 - 0.42 | 0.5 - 0.8 | 0.17 - 0.37 | <0.030 | <0.030 | 0.8 - 1.1 | - | <0.3 | - | - | <0.3 | - | - | |
| EN | 37Cr4 - 1.7034 | ||||||||||||
| 0.34 - 0.41 | 0.6 - 0.9 | <0.40 | <0.025 | <0.035 | 0.9 - 1.2 | - | - | - | - | - | - | - | |
| GOST | 38ChA - 38KhA - 38ХА | ||||||||||||
| 0.35 - 0.42 | 0.5 - 0.8 | 0.17 - 0.37 | <0.025 | <0.025 | 0.8 - 1.1 | <0.15 | <0.3 | <0.05 | <0.03 | <0.3 | <0.008 | <0.2 | |
| DIN | 38Cr4 - 38 Cr 4 - 1.7043 | ||||||||||||
| 0.34 - 0.40 | 0.6 - 0.9 | 0.15 - 0.40 | <0.025 | <0.035 | 0.9 - 1.2 | - | - | - | - | - | - | - | |
| PN | 40H | ||||||||||||
| 0.36 - 0.45 | 0.5 - 0.9 | 0.17 - 0.37 | <0.035 | <0.035 | 0.8 - 1.2 | - | <0.3 | - | - | - | - | - | |
| PN | 40HA | ||||||||||||
| 0.36 - 0.44 | 0.5 - 0.8 | 0.17 - 0.37 | <0.025 | <0.025 | 0.8 - 1.1 | - | <0.3 | - | - | - | - | - | |
| EN | 41Cr4 - 1.7035 | ||||||||||||
| 0.38 - 0.45 | 0.6 - 0.9 | <0.40 | <0.025 | <0.035 | 0.9 - 1.2 | - | - | - | - | - | - | - | |
38HA, 37Cr4, 1.7033 - specification and destination
Structural steel for thermal improvement on medium-duty parts, easily machined in a softened state. Products of the 38HA grade are typically used for components up to 40 mm in dimensions, achieving the best results with hardening in oil. Steel is easily subjected to thermo-mechanical treatment but is not suitable for welding.
Products of this grade can be hardened and tempered at temperatures of 200 - 350 ℃, resulting in a hardness range of 35 - 45 HRC used in rolls or guides. The second possibility is surface hardening after thermal improvement, where the surface hardness of the material closes in the range of 54-59 HRC.
The 38HA grade, compared to the popular 40H, differs in the narrowed carbon range in chemical composition, and lower content of sulfur-S, and phosphorus-P in chemical composition.
Materials of the standard are referred to as permanent of special purpose. From the above grade steel are made, among others, fuel pumps, abrasive wheels, exhaust valves, gears, nuts, bolts, steering parts, and piston rods in motor vehicle construction. In addition, steel is used for such parts of turbines as rotors and toothed-wheel rims in gearboxes.
Bearing in mind welding issues, you should avoid it and weld the components in exceptional situations in the softened state by heating the product earlier depending on the dimensions to the 150-350 ℃ range. It can be arc welded and CO2 welded.
Indicative mechanical properties of 38HA and 40H steels
| Properties | Dimensions | ||||
|---|---|---|---|---|---|
| <16mm | 16 - 40mm | 40 - 100mm | 100 - 160mm | 160 - 250mm | |
| Tensile strength Rm (kG/mm2) | 80 - 90 | 65 - 80 | 50 - 65 | 50 - 65 | 45 - 60 |
| Yield point Re (kG/mm2) | 100 - 120 | 90 - 105 | 80 - 95 | 75 - 90 | 70 - 85 |
| Elongation A (%) | 10 - 13 | 11 - 14 | 12 - 15 | 13 - 16 | 13 - 16 |
| Impact resistance KM (kGm/cm2) | 6 - 8 | 6 - 8 | 5 - 7 | 4 - 5 | 4 - 5 |
Thermal treatment
- normalizing at 840 - 870℃
- softening at 680 - 720℃
- Hardening with cooling in in water or oil
- hardening (I) at 820 - 850℃
- hardening (II) at 850 - 870℃
- Tempering at 500 - 670℃
In the above grade Rolex Metal supplies:
Other indications and equivalents of 38HA steel:
38H, 37Cr4, 1.7034, 37 Cr 4, 7034, 38Cr4, 38 Cr 4, 1.7043, 40H, 40HA, 45H, 38ChA, 35ChA, 38CrA, 38ХА, 35ХА, 37Х